July 2011 included an extra Friday and Saturday and an Independence Day that fell on a Monday, giving gamblers a chance to extend the holiday weekend.

The Fourth last month came on a Wednesday. And there was no extra weekend to boost winnings.

The Division of Gaming Enforcement said that for June and July combined, revenue was down 5.5 percent from the same period last year.

At Borgata Casino Hotel & Spa, the city's biggest money-making casino, Joe Lupo, the senior vice president for operations, said a single gambler was responsible for about half the casino's 16 percent decline from a year earlier. The gambler, he said, won $5 million in a single hot streak of a weekend.

It's not clear whether the casino should be heartened or disheartened that the big winner is a regular customer and is sure to be back.

"When you deal with the big action, you have big fluctuations like that," Lupo said.

Across the city, only two casinos that were open a year ago had a better July this year than last. One was Golden Nugget Atlantic City, which brought in more than $77 million, a nearly three-fold increase in revenue from a year earlier when it was in just its second full month of operating under a new name. The casino was previously Trump Marina.

The other casino with improvements was the Tropicana Casino & Resort, where revenue increased by 4.4 percent.

While a harsh calendar contributed to July's struggles in the city, the weather could boost August. Last year, casinos shut down for a weekend when Tropical Storm Irene hit the coast nearby, hurting the city's fortunes.

But last year's problems increase the chance that the city will bring in more from gamblers in the same period this year.